<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="../util.js"></script>
</head>
<body>
<select onchange="onChange(this.value)">
    <option value ="volvo">Volvo</option>
    <option value ="saab">Saab</option>
    <option value="opel">Opel</option>
    <option value="audi">Audi</option>
</select>

<script>
    
    function onChange(val) {
        log(val);
        alert("输入值已更改。新值是：" + val);
    }
</script>

</body>
</html>